JPS6378537A - Treater - Google Patents

Abstract

PURPOSE:To improve the efficiency of treatment by forming treating tank itself in rotatable structure, shaping a projection for agitation to the inner wall surface of the tank and forming a liquid current to a substance to be treated positioned in the tank. CONSTITUTION:When a holder 8 in which wafers 2 are housed is lowered and positioned at a predetermined position in a treating tank 4 and the inside of the treating tank 4 is filled with a washing 3, a motor 5 starts its revolution. When the treating tank 4 interlocked with the motor 5 is turned, a vortex flow is generated in a washing 3 in the treating tank 4 by the action of projecting sections 6 for agitation shaped to the inner wall of the treating tank 4. When the flow of such a washing 3 passes on the surfaces of the wafers 2, chemicals such as a strong acid solution adhering on the surfaces of the wafers 2 are detached from the wafers 2, and the surfaces of the wafers 2 are cleaned. Since revolution in both forward and opposite directions is changed over at every fixed time in the motor 5 and the direction of the vortex flow generated in the washing 3 is also inverted, flows from two directions are passed alternately to the surfaces of the wafers 2 at every fixed time. Accordingly, the effect of washing of the wafers 2 is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a technology that is effective when applied to cleaning processing and chemical treatment, for example, in the so-called pre-process of semiconductor wafers in the manufacturing process of semiconductor devices. This technology is effective for use in wafer cleaning performed at

[Conventional technology]

Regarding cleaning technology for semiconductor wafers (hereinafter simply referred to as "wafers"), for example, Kogyo Kenkyukai Co., Ltd., 1982
Published on November 10th, ``Electronic materials November 1981 issue special issue, VLSI manufacturing and testing equipment guidebook JP100 ~
101. The outline explains the wafer cleaning method. For example, the wafer is treated with strong acid, then washed with pure water, then the thin film is etched away with a diluted hydrofluoric acid solution, and then the wafer is cleaned with pure water. The techniques used are explained.

The present inventor studied the above-mentioned wafer cleaning with pure water and chemical treatment technology. The following are the techniques studied by the present inventor, and the outline thereof is as follows.

In other words, processing tanks used in wafer chemical processing or cleaning processes using pure water have a rectangular or circular cross-sectional structure, and processing liquid is supplied into the processing tank from below. It is known that processing is performed by immersing a wafer in a processing solution with the processing solution overflowing from the upper periphery of the processing tank.

[Problem that the invention seeks to solve]

However, the inventors have discovered that the above treatment tank structure has the following problems.

First, with the above technique, it is not possible to efficiently generate a flow of the processing liquid in the tank, and it is not possible to ensure a sufficient flow rate of the processing liquid to the surface of the wafer.

Therefore, a large amount of processing liquid is required, and the cleaning efficiency cannot be said to be good.

Second, in the above technology, foreign particles floating near the center of the water surface of the tank ride the flow of the overflow state, and therefore remain suspended in the processing solution for a long time, attaching to the surface of the wafer, and causing damage to the wafer. It may cause defects.

Thirdly, in the above-mentioned technique, usually only wafers housed in one cartridge can be processed in one processing tank, so processing efficiency is not good.

From this point of view, it is conceivable to install a rotating propeller or the like in the tank to forcibly generate a swirling flow in the processing liquid in the tank, thereby ensuring the flow rate of the processing liquid to the wafer surface.
With this technology, the problem occurs due to the presence of mechanical sliding parts.
There is also a possibility that the wafer may be contaminated by foreign particles.

It is also conceivable to rotate the wafer cartridge itself within the tank, but there is also a risk that the wafers will be damaged due to collisions between the wafers or between the wafers and the cartridge.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a technology for liquid treatment of objects to be treated with a favorable treatment temperature.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

A brief overview of typical inventions disclosed in this application is as follows.

That is, the processing tank itself has a rotatable structure, and stirring protrusions are provided on the inner wall surface of the tank to generate a liquid flow for the object to be processed moved inside the tank.

[Effect]

According to the above-mentioned means, since the tank itself has a rotating structure,
Since a sufficient flow of processing liquid can be secured to the object to be processed without damaging the object, processing efficiency can be significantly improved.

〔Example〕

FIG. 1 is an explanatory cross-sectional view showing a wafer cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view thereof.

The processing apparatus of this embodiment is a wafer cleaning apparatus 1 used in the pre-process of wafers in the manufacture of semiconductor devices, and is used for cleaning wafers 2 after performing strong acid treatment such as hydrofluoric acid or ammonia. This is to clean the wafer surface by removing the chemical liquid that has adhered to the surface.

This wafer cleaning apparatus 1 has a cleaning liquid 3 (
This processing tank 4 is connected to a morph 5 provided below the processing tank 4, and the tank itself is rotatable.

A stirring protrusion 6 is provided at a predetermined portion of the inner wall surface of the processing tank 4, and when the processing tank 4 is rotated by the action of the stirring protrusion 6, the cleaning liquid 3 in the processing tank 4 is stirred and Id: to form a swirling flow within.

As shown in FIG. 2, holders 8 for fixing the cartridges 7 in which the wafers 2 are housed extend in the substantially central part of the processing tank 4 in a crosswise direction.
(4 cars) It has a structure that allows IJ 7 to be fixed. The car 1-IJ edge 7 is made of, for example, fluororesin, and one cartridge 7 can accommodate, for example, a predetermined number of wafers 2 in parallel in the longitudinal direction of the cartridge 7. The holders 8 are supported from above the processing tank 4 by a shaft 9 attached to the connecting center of each holder, and this shaft 9 can be moved up and down in the axial direction by an elevator mechanism (not shown). Therefore, as the shaft 9 moves in the axial direction, each holder 8 is moved in and out of the processing tank 4, and the wafer 2 can be immersed and taken out.

The inside of the shaft 9 has a double pipe structure, with an inner pipe 9a
It is divided into a drainage channel 10 formed by the inner surface of the inner tube 9a and a water supply channel 11 formed by the outer surface of the inner tube 9a and the inner surface of the outer tube 9b.

A large number of water supply ports 12 are provided on the side surface of the outer tube 9b of the shaft 9 and communicate with the water supply channel, and the cleaning liquid 3 is supplied into the processing tank 4 through the water supply ports 12. On the other hand, the shaft 9 opens to the inside of the processing tank 4 at the lower end, that is, at the bottom of the holder 8, and this opening substantially functions as a drain port 13. That is,
A part of the cleaning liquid 3 in the processing tank 4 is discharged from the drain port 13.

An auxiliary tank 14 is formed around the processing tank 4 and is connected to the processing tank 4 so as to surround the periphery of the processing tank 4. A drain port 15 is provided at the bottom of the auxiliary tank 14. There is. Drain channels 17 are provided below the drain ports 15 and are connected to drain pipes 16, respectively. Therefore, the cleaning liquid 3 overflowing from the periphery of the processing pi 4 is transferred to the auxiliary tank 14.
The waste water then falls to the ground and is further discharged to the outside through a drain pipe 16 through a drain channel 17.

Next, the operation of this embodiment will be explained.

When the wafer 2 is accommodated in the cartridge 7 and fixed at a predetermined position in the holder 8, the holder 8 is lowered and positioned at a predetermined position within the processing tank 4.

Next, the cleaning liquid 3 is supplied into the processing tank 4 from the water supply port 12 via the water supply channel 11 of the shaft 9, and when the inside of the processing tank 4 is filled with the cleaning liquid 3, the motor 5 starts rotating.

When the processing tank 4 that is linked to the motor 5 is rotated as the motor 5 rotates, the cleaning liquid 3 in the processing tank 4 is Creates a swirling flow. When the flow of the cleaning liquid 3 passes over the surface of the wafer 2, the chemical liquid such as a strong acid solution attached to the surface of the wafer 2 is removed from the wafer 2, and the surface of the wafer X2 is cleaned. Note that the rotation of the motor 5 is controlled so that forward rotation and reverse rotation are repeated at predetermined time intervals. Therefore, as the rotation is switched between the forward and reverse directions, the direction of the swirling flow generated in the cleaning liquid 3 in the processing tank 4 is also reversed, so that the surface of the wafer 2 is exposed to the flow from two directions at predetermined intervals. will be passed alternately. In this way, by passing the flow in both the forward and reverse directions on the surface of the wafer 2, it is possible to prevent the chemical solution from remaining on the uneven portions formed on the surface of the wafer 2, thereby increasing the cleaning effect of the wafer 2. can.

On the other hand, when the motor rotates 50 times, the cleaning liquid 3 is sequentially supplied into the processing tank 4 from the water supply port 12 of the shaft 9. The cleaning liquid 3 thus supplied into the processing tank 4 flows in a spiral shape within the processing tank 4, and then overflows from the drain port 13 at the tip of the shaft 9 or the periphery of the processing tank 4, and flows into the auxiliary tank 14 and drains. The water is drained via channel 17.

In this way, after repeating the forward and reverse rotation of the motor 5 a predetermined number of times, the rotation of the motor 5 is stopped and the holder 8
is lifted out of the processing tank 4, and the cleaning process is completed.

As described above, according to this embodiment, the following effects can be obtained.

(1) By making the processing tank 4 itself a rotating structure and forcibly generating a swirling flow in the cleaning liquid 3 in the processing tank 4, the cleaning liquid 3 can be flowed over the surface of the wafer 2 with high efficiency. 2. The cleaning efficiency can be improved.

(2) According to (1) above, it is possible to efficiently clean a large number of wafers 2 with a small amount of water, and thus the cost of the cleaning process can be reduced.

(3) According to (1) above, the floating foreign matter in the cleaning liquid 3 is efficiently removed to the outside by the swirling flow generated in the processing tank 4, so that the wafer is contaminated by the floating foreign matter in the cleaning liquid 3. can be prevented.

(4) By providing the processing tank 4 itself with a rotating structure, damage to the wafers 2 due to contact between the wafers 2 or between the wafers 2 and the cartridge 7 can be prevented.

(5) By reversing the rotational direction of the motor 5 at predetermined intervals, the flow direction of the cleaning liquid 3 flowing on the surface of the wafer 2 is changed, so that the chemical liquid that adheres to the stepped portions etc. on the surface of the wafer 2 is changed. It is also possible to remove foreign substances such as
The cleaning efficiency can be further increased.

(6) According to (1) to (5) above, the yield of wafers 2 can be improved and a highly reliable semiconductor device can be provided.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor. For example, a case has been described in which the holder 8 is moved up and down when immersing the wafer 2 in the cleaning liquid 3 or when taking it out from the cleaning liquid 3.
The processing tank 4 may be moved up and down.

In the above explanation, the invention made by the present inventor is mainly applied to the field of application, which is so-called wafer cleaning processing technology, but the present invention is not limited to this, and other chemical liquid processing of wafers is The present invention can also be applied to a chemical liquid processing apparatus for liquid processing, or a processing apparatus for liquid processing objects other than wafers.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, by adopting a processing apparatus structure that includes a processing tank that is rotatable and has a stirring protrusion on the inner wall surface of the tank, and a holder that is held in a fixed position in the processing tank and supports the object to be processed during processing, The object to be treated can be efficiently immersed in the flow of the forcibly generated treatment liquid, and the treatment efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view showing a wafer cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing the wafer cleaning apparatus according to the embodiment. DESCRIPTION OF SYMBOLS 1... Wafer cleaning device, 2... Wafer, 3... Cleaning liquid, 4... Processing tank, 5... Motor, 6... Stirring protrusion, 7... Cartridge, 8...・Holder, 9
...shaft, 9a...inner tube, 9b...outer tube, 1
0... Drain channel, 11... Water supply channel, 12... Water supply port, 13... Drain port, 14... Auxiliary tank, 15... Drain port, 16... Drain pipe, 17 ...Drainage channel. Agent: Patent Attorney Katsuo Ogawa＼8, Figure 2

Claims (1)

[Claims] 1. A processing device that includes a processing tank that is rotatable and has a stirring protrusion on the inner wall surface of the tank, and a holder that is held in a fixed position in the processing tank and supports the object to be processed during processing. . 2. The processing apparatus according to claim 1, wherein the processing tank is controlled so that the direction of rotation of the processing tank is reversed at predetermined intervals. 3. The processing according to claim 1 or 2, wherein the holder is held by a tube, and the processing liquid is supplied or drained through a passage formed in the tube. Device.